libhevcenc: Update 32 bit chroma neon modules to avoid reading an extra byte am: 42fb245a7b am: 2a3b4e76f9 am: ffb1b735ac am: 594b4a5133

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libhevc/+/15163641

Change-Id: I4502888e79d9c4478f7b95bc6567a24160feab20